PolitiFact's guide for Iowa caucus-goers

Supporters of Ron Paul are hoping they can outrun the other candidates at the Iowa caucuses.

Duck, or you might get splattered.

The campaign mudslinging on TV, on the web and in mailboxes, has made for a dirty December. But now it’s finally time for the voters to have their say about the Republican candidates for president.

To help you cut through the murky messages, we're offering this guide to the attacks that left you scratching your head and wondering, "Is that true?"

Against Mitt Romney

Did he remove health care passage from paperback? Texas Gov. Rick Perry and others have claimed that Romney changed the paperback edition of his book No Apology to delete a sentence stating the Massachusetts health care program should be extended to all Americans. The line was edited, but not to the extent Perry and others said. PolitiFact rated it Mostly False.

Did the Massachusetts health care plan "kill jobs"? On the campaign trail and in a TV ad, Perry charged that Romney’s health care program "killed 18,000 Massachusetts jobs." We found that the toll wasn’t what Perry said -- his claim was based one study that suggested 18,000 jobs were not created because of the health law’s costs to businesses -- not that 18,000 existing jobs were destroyed. Mostly False.

Socialized medicine for the Bay State? During a December debate, Bachmann charged that Romney is "the only governor that put into place socialized medicine." That’s government-funded and government-provided health care. The Massachusetts plan Romney put in place is no such thing. Pants on Fire.

Obedience to the Mormon church. In one of the more extreme attacks of the campaign (so far), little-known Republican candidate Fred Karger claimed that "if a President Romney got a call from the president of the (Church of Latter Day Saints), he has no choice but to obey. It is obedience over family and country." A Mormon church spokesman called the claim "simply ridiculous." We called it Pants on Fire.

Downplaying foreclosure crisis. The Democratic National Committee went after Romney’s position on the foreclosure crisis, saying in an ad that his solution was to let the process "run its course and hit the bottom." But the ad left out the part where he said the market would then rebound as investors buy homes and fix them up. Our ruling: Half True.

Flip-flop on health care law. In another ad, the DNC said Romney flip-flopped on supporting the national health care law, claiming he first supported it and then opposed it. But we found that Romney never endorsed President Obama’s health care legislation and rated it Mostly False.

Flip-flop on abortion. In a web ad, Jon Huntsman said Romney flip-flopped on abortion, switching from pro-choice to pro-life. True.

Against Newt Gingrich

"Godfather of gridlock." David Axelrod, a senior Obama adviser, bestowed Gingrich with the nickname "the godfather of gridlock," blaming the former House speaker for the no-compromise climate in Washington. But we found plenty of examples to dub Gingrich a dealmaker too. Half True.

Does his immigration plan grant amnesty? Romney says Gingrich’s immigration plan provides "a new doorway to amnesty." We found that’s largely accurate, depending on how you define "amnesty." Mostly True.

Child labor. Conjuring images of 9-year-olds sewing sneakers together, Romney told Fox News in December that Gingrich "has said that we ought to get rid of our child labor laws." We found that Gingrich favors loosening the laws but not scrapping them. Mostly False.

Ethics violations in Congress. A pro-Romney "super PAC" known as Restore Our Future released a TV ad in mid December chock full of Gingrich attacks. One of them said he was fined $300,000 for ethics violations. True.

Public funding for abortions. Restore Our Future claimed Gingrich "supported taxpayer funding of some abortions." We found he had supported a restriction on abortion funding favored by many conservatives. Half True.

Against Ron Paul

Opposition to marriage licenses.New York Times columnist Gail Collins caught our attention when she wrote that Paul "doesn’t believe in marriage licenses." Turns out, she’s right, based on Paul’s own writings. True.

Abolishing FEMA. Another New York Times columnist, Maureen Dowd, said Paul wants to shut down the Federal Emergency Management Agency. Again, various statements by Paul back that up. True.

Against Rick Perry

Jobs for illegal immigrants. Romney said in October that 40 percent of the job growth in Texas went to illegal residents. We found a bit of cherrypicking going on. Half True.

More illegals on Perry’s watch? Romney charged in an October debate that Texas’ illegal immigration population rose 60 percent during a decade that Perry was governor. We explained that Perry alone can’t be blamed for that. Half True.

Against Michele Bachmann

A failure in Congress? Before he dropped out of the race, former Minnesota Gov. Tim Pawlenty attacked his in-state rival on her legislative record, which he said amounts to "offering failed amendments." We checked and found that, indeed, she had a low batting average. Mostly True.

Farm subsidies? Questioned about her in-laws’ Wisconsin farm, in which she and her husband have a stake, Bachmann insisted she has "never gotten a penny" from it in the form of federal subsidies. But financial records don’t match up with her statements. False.

Against Jon Huntsman

Did he favor Republican changes to Medicare? The New Hampshire Democratic Party leveled an attack on Huntsman before he visited the Granite State in August, saying he supported changes in Medicare that would deny guaranteed benefits to 980,000 New Hampshire residents. We found that the claim went too far. Half True.

Stance on stimulus. Former Democratic New Hampshire Rep. Richard Swett accused Huntsman in July of accepting $14.4 billion in stimulus funds for Utah and saying the program wasn’t big enough, then later claiming he never supported it. It’s true he took the money, but we found his position has vacillated wildly. Half True.